The Moxie is an instrument for the scientific demonstration of the extraction, in local conditions, of oxygen (O2) from carbon dioxide (CO2) which almost exclusively makes up the Martian atmosphere. Moxie first stores and compresses CO2, then, through an electrolytic reaction, divides the CO2 molecules into O2 and carbon monoxide (CO).
The instrument is made up of three modules, the first is the CAC (The (CO2) Acquisition and Compression), i.e. the compressor, which sucks CO2 from the atmosphere and compresses it to ~ 1 atm. The O2 output flow is separated from that of O2 and CO, this to allow better verification of the quantity of oxygen produced.
Furthermore the current passing through the SOXE is a direct result of the oxide ions passing through the electrolyte and this provides an independent measurement of the rate of O2 production produced. The measurement of the quantity of O2 output is measured by the third module.
Everything is managed by electronics that collects the data and sends them towards Earth. The MOXIE weighs no more than 1.8 kg and has a power consumption of 300 W. The pressurized gas is then supplied to the second module, the SOXE (Solid OXide Electrolyzer), i.e.
the module where the electrolytic reaction takes place: 2CO2 → O2 + 2CO where the O2 is produced at the anode, it is equivalent to the process of a fuel cell in reverse. The SOXE operates at a temperature of approximately 800 °C, therefore requiring sophisticated thermal protection, including pre-heating of the incoming gas and cooling of the outgoing gas.
Thanks to the MOXIE, NASA has managed to produce oxygen on Mars, successfully completing a sensational experiment. MOXIE generated a total of 122 grams of oxygen, comparable to how much a small dog breathes in about 10 hours.
At its maximum efficiency, the device produced 12 grams of oxygen. Having finally completed all of its tasks, it is clear that engineers on the ground will have much to learn from these findings. Trudy Kortes, director at NASA, added: "We are proud to have supported a technological breakthrough like MOXIE, capable of transforming local resources into useful products for future exploration missions." NASA Deputy Administrator Pamela Melroy explained: "MOXIE's incredible performance shows that it is feasible to extract oxygen from the Martian atmosphere, which could provide breathable air and even rocket propellant for future astronauts."